Exterior wall with ETICS or exterior wall with lightweight plaster?

super..thank you very much..

and in the topic of mold, diffusion moisture, etc....is there a difference there..is a ventilation system advisable????

Yes, a ventilation system is definitely advisable, because no matter how you build... moisture will not disappear through the walls...

Of course, you can ventilate several times a day, but then on all floors and with windows completely open for several minutes... but who can do that nowadays? We humans plus plants etc. bring additional moisture into the house daily on top of the building moisture. If heating is too low and there is only minimal air exchange (windows tilted etc.), then it starts... because nowadays houses are practically plastic bags (which is not necessarily bad)

So as I said, nowadays I would neither buy nor have a house built without [Kontrollierte-Wohnraumlüftung].

Hello Marcel,

I would not reduce the difference between the two construction methods to purely philosophical terms; in my opinion, the variants also differ greatly in terms of building physics and construction technology.

24cm porous hollow brick plus 8.0cm insulation (polystyrene rigid foam boards), reinforcement layer and finishing plaster

Here you are basically building another house around the brick house: one made of styrofoam. I am deliberately leaving aside the philosophical views on this topic in order not to trigger a wildfire or fundamental discussions. The mere fact that, unlike a "normal" house where the finished walls receive plaster, an additional constructive layer of various materials with considerable thickness is added, increases not only the effort but also the possibility of errors and problems to the same extent.

This includes the many additional steps (fastening the insulation, arranging the boards without gaps, more elaborate reinforcing, very critical selection of the plaster, constructive consideration of the 8 cm thick build-up at window sills, roller shutters, etc.) as well as the additional occurrences in later life with a styrofoam facade (holes caused by woodpeckers & co., damage from leaning bicycles, possibly moisture and insect ingress into damaged areas or behind the boards due to faulty processing, risk of the facade turning green from algae, chipping due to normal weathering over the years, etc.).

Just walk through the streets with open eyes and look at styrofoam facades that were glued/doweled on a few years ago and judge for yourself. Sometimes one’s own observations help enormously in decision-making.

36.5cm porous hollow brick and 2.0cm lightweight plaster with fabric reinforcement should be built.

Here you avoid all the above-mentioned additional problems with a few centimeters thicker brick. The facade work is limited to setting the plaster profiles, embedding the reinforcement and subsequently applying the plaster to a total thickness of 2 cm. That’s it.

The plaster should be precisely matched to the brick in order to optimize the temperature curve / dew point in the system.
Insulating plaster / lightweight plaster is also available with purely mineral additives, so you can completely do without styrofoam – even in powder form – if you like. The plaster regulates stresses, moisture, and weathering stresses in a layer thickness of 2 cm – not in a thin layer of a few millimeters like the plaster on ETICS systems – as well as, if applicable, attacks by woodpeckers or bicycles. I intentionally give no valuation on this but merely list the facts.

Regards

@Allrounder:

you should also add to your facts that plaster flaking can occur on both monolithic and ETICS façades. And algae can occur not only on ETICS but also on monolithic walls. The probability is just as high in practice with the same U-value. Algae don’t care what material is under the plaster. ;)

The reason the monolithic walls do not develop algae is due to lower U-values of the walls in PRACTICE. Although the plaster in the ETICS cools down faster, it also heats up again more quickly.